What if we’re on Datadog/New Relic and not Prometheus?

Same pattern. Replace PromQL with metric queries or monitors. Argo Rollouts supports Datadog. Flagger supports Datadog and CloudWatch. Key is pre-aggregated, fast-compute metrics and labels for `service.version` and `rollout.phase`.

We already have feature flags. Why do we need canaries?

Flags are great for isolating code paths, but they don’t protect infra and cross-service regressions. Canaries validate the whole slice: app, service mesh, DB, cache. Use both: flags to limit blast radius within the canary, canary to limit blast radius overall.

Can we do this without Kubernetes?

Yes. Use your LB to split traffic (NGINX, Envoy, ALB weighted target groups) and use Spinnaker, CodeDeploy, or LaunchDarkly Experiment for progressive traffic. The analysis gates remain the same.

How do we handle mobile where rollbacks are slow?

Instrument crash-free sessions and key action success rates by app version. Use server-side flags to kill new flows and feature gates to block broken versions. Rollouts apply to backend endpoints those apps hit; stop the bleed there.

Won’t this slow down deployments?

It’ll slow down bad deployments. Good ones sail through with short pauses and green checks. Teams typically regain throughput because they spend less time firefighting and doing late-night rollbacks.

Reliability-observability · Oct 14, 2025 · 10 minute read

The Canary That Saves Your Quarter: Instrument Release Health Before Customers Scream

If your release dashboard says "all green" while revenue quietly nose-dives, your telemetry is lying to you. Here’s how to wire leading indicators into your rollout so regressions never reach production blast radius.

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The Canary That Saves Your Quarter: Instrument Release Health Before Customers Scream

Key takeaways

Implementation checklist